An automixer is typically designed to balance multiple sound sources, usually microphones, based on the level of each source, attenuating inactive inputs. Automixers are typically used to mix panel discussions on television shows and at conferences and seminars. They can also be used to mix actors' wireless microphones in theater productions and musicals. They may be used in audio systems in churches, schools, hotels, convention centers, and the like. They are frequently employed in commercial sound systems such as in courtrooms and city council chambers where it is not expected that a live sound operator will be present to mix the microphones. When automixers are used in live sound reinforcement, they work to maintain a steady limit on the overall signal level of the microphones. If a public address system is set up so that one microphone will not feed back, then, in general, multiple microphones will not feed back if they are automixed.
Further, various gain-sharing strategies have been developed in which the signal level in a particular channel is compared with the sum of all the channels to compute a gain-sharing factor. The channel with the highest level input receives highest gain which is a proportional fraction of the total gain available. Additionally, gain-sharing strategies have been developed in which a proportional, multichannel gain-sharing audio circuit has a gain control in the computing leg so that additional weight may be accorded the channel so that the channel is allocated greater gain in proportion to the total amount of signal available to all of the channels combined.